YELLOWTAIL FLOUNDER OFF NEW ENGLAND 



229 



We think that few flounders were landed from 

 the Nantucket Shoals area in the late twenties 

 because the fish were scarce and not just because 

 it was the practice in the fleet to discard them. In 

 the first place, large quantities of both haddock 

 and yellowtail have never been caught on the same 

 grounds at the same time in other parts of the 

 New England Banks. Secondly, had the abun- 

 dance of yellowtail in the twenties equalled that 

 found on those grounds in 1942 when production 

 by a small trawler reached nearly 20,000 pounds 

 a day, it would have created so much work in sort- 

 ing that fishermen not wanting the yellowtail 

 would have moved to other areas. On the other 

 hand, the subsequent failure of these grounds to 

 produce haddock no doubt was due to a lack of 

 haddock and not to a failure to fish for them. 

 Haddock has been a much sought-after species on 

 the New England Banks, and when vessels began 

 to fish the grounds for yellowtail after 1940 it is 

 certain that any significant haddock concentra- 

 tions would have been discovered and fished, had 

 they existed. 



Coincident with the fishery for haddock on the 

 grounds near Nantucket Shoals was the occur- 

 rence of yellowtail farther west off the coast of 

 New Jersey. The presence of adults there during 

 the spawning season is indicated by the capture of 

 eggs and larvae in 1929 and 1932, as discussed in 

 the preceding section. These eggs and larvae 

 could not have been found consistently off the 

 New Jersey coast if the spawners had been off 

 southern Massachusetts, as they were after 1942. 

 The residual drift of the waters on the shelf is 

 slowly westward, but as Sette (1943) and Ketch- 

 um et al. (1951) have found, the surface water 

 is drifted primarily by the wind. The wind di- 

 rection is variable, but during May it is usually 

 southwesterly (Sette 1943, p. 205), though it was 

 northeast in 1932. Furthermore, the rate of drift 

 was found by both investigators to be in the order 

 of 10 miles a day or less. Since hatching occurs 

 in 10 days or less and the "small" larval stage 

 lasts only about 10 days, the spawning adults evi- 

 dently were not far from the places where the 

 eggs and larvae were found. 



During the course of his mackerel investiga- 

 tions, 1925-32, Sette gained the impression that 

 the yellowtail was consistently one of the principal 

 spring spawners in the area. In 1932, the only 



476995 O — 59 5 



year for which comparative data are available, 

 the mackerel larvae were 1.97 times as numerous 

 as yellowtail larvae in the tows of the first six 

 cruises ( Sette 1943. table 19 ; our appendix table 

 E-l, p. 256) . The yellowtail was the second most 

 abundant species in the tows; consequently, the 

 number of adults must have been large. The pop- 

 ulation of mackerel in 1932 was estimated at be- 

 tween 45,000,000 and 400,000,000 by Sette. We 

 may surmise that yellowtail have similar fecun- 

 dity, if we balance the slightly greater size of 

 the egg of the mackerel against the slightly 

 smaller size of the yellowtail. If so, the popula- 

 tion of yellowtail was in the order of at least some 

 tens of millions. Too, the limited migratory 

 habits of the species indicate that it must have been 

 a resident population, not a coastwise migrant like 

 the mackerel. 



Why such an abundant fish was not well known 

 before 1935 is not clear, but we have mentioned 

 that yellowtail were not marketed in those earlier 

 years, they rarely occur within 10 miles of shore, 

 and they are not easily caught by hooks: so it 

 seems entirely possible that they were present but 

 were not fished. On the other hand, any such con- 

 centration of yellowtail as was found after 1942 

 would have been fished, for enough small otter 

 trawlers operated off the New Jersey coast to have 

 found the fish if they had been there. 



The second radical faunal change on the yellow- 

 tail grounds occurred after the decline in the 

 southern New England stock. With yellowtail 

 especially scarce in 1949 and with an expanding 

 market for fish meal, the fishermen turned to 

 "trash" fish, which they sold to the reduction 

 plants. They saved everything they caught in 

 their nets, but the principal species taken were red 

 hake (Urophycis chuss), eelpout (Zooms anguil- 

 laris), and several species of skates of the genus 

 Raja (Sayles 1951). The principal fishing ground 

 at the start of this fishery in 1949 was in from 10 

 to 20 fathoms of water south of the eastern end of 

 Martha's Vineyard, and a secondary center was 

 located about 15 miles southeast of this point. 

 Both of these grounds had previously produced 

 substantial quantities of yellowtail (fig. 2), and 

 yet very few yellowtail were included in the catch 

 of the trash fishery. After 1949, this fishery 

 spread over more of the yellowtail grounds, fish- 

 ermen reported. 



